The invention relates to the field of kinetic energy and thermal energy harvesting, mixing, vacuum and pumping technology, in which it is possible to organize the process of efficient kinetic and thermal energy harvesting and create thrust and vacuum by utilizing the interparticle kinetic energy of the liquids in a closed or an open loop.
Known method of heating liquids, includes an electric or steam driven pump, indirect and direct contact heat exchangers and jet apparatuses supplied with thermal energy from boilers or district energy systems, where liquids are heated by steam or hot water supply (see for example Reference-1: Oliker, I. Demonstration of Performance and Energy Efficiency of Fisonic Devices at the Con Edison Test Facility, NYSERDA Report #20346). The heated water is transported to the consumers (end users). After transferring the heating energy to the user, the cooled liquid/condensate collected in condenser and is transported in a closed loop back to the heat source by the pump and the cycle repeats again. Make-up fluid is provided to the system when the fluid is not returned from the end user. This method consumes a substantial amount of thermal and pumping energy for heating and transportation of the liquid.
Many jet-type devices for heating and transporting liquids, steam, gases and solid materials are used in the industry. These jet-type devices include Venturi de-superheaters, steam ejectors, jet exhausters and compressors, jet eductors and jet vacuum pumps.
The typical jet-type device consists of three principal parts: a converging (working) nozzle surrounded by a suction chamber, mixing nozzle and a diffuser. The working (motive) and injected (entrained) streams enter into the mixing nozzle where the velocities are equalized by exchange of energy and the pressure of the mixture is increased. From the mixing nozzle or multiple nozzles the combined stream enters the diffuser where the pressure is further increased. The diffuser is so shaped that it gradually reduces the velocity and converts the energy to the discharge pressure with as little loss as possible. The jet-type device transforms the kinetic energy of the working stream to the injected stream by direct contact without consumption of mechanical energy. The jet-type devices operate with high expansion and moderate or high compression ratios and require a continuous motive force.
During the interaction of two streams with various velocities an increase in entropy of the mixed stream takes place (as compared with an invertible mixing), resulting in the reduction of the pressure of the discharged stream. Therefore, typically the discharge pressure of the jet-type device is higher than the pressure of the injected stream but lower than the pressure of the working stream.
The disadvantage of jet-type devices is that jet-type devices use high level kinetic motive force to perform work, which degrades the outlet pressures, drastically reduces the effectiveness of initial energy input ratios and requires a continuous motive force. Therefore these devices cannot be used to escalate pressure to a higher output level. Other devices, such as devices that operate based on what is known as Fisonic technology can utilize a lower energy input and escalate the initial thrust and thermal load. Fisonic technology design achieves this by exploiting the two-phase flow's very low Mach number and harvesting a minute amount (<0.1%) of the system's thermal energy and converting it to kinetic thrust.
In the Fisonic device (“FD device”) the injected water/fluid enters the mixing chamber with high velocity in parallel with the velocity of the working stream. The injected water/fluid is typically supplied through a narrow circumferential channel surrounding the working nozzle. The mixing chamber typically has a conical shape. The optimized internal geometry of the FD device causes the working and the injected streams to mix and accelerate, creating transonic conditions, breaking the stream into tiny particles and changing the state of the mixing streams into plasma conditions, and finally converting the minute fractions of the streams thermal energy to physical trust (pump head) with the discharge pressure higher than the pressure of the mixing streams. The main reason behind this phenomenon is the high compressibility of homogeneous two-phase flows. It was demonstrated that uniform two-phase flows have more compressibility than the flows of pure gases. Hence the possibilities of the more effective conversion of thermal energy into the mechanical work in uniform two-phase mixtures especially in the transonic or supersonic modes.
The sonic speed in such systems is much lower than the sonic speed in liquids and in gas. As one can see from FIG. 1 the minimum sonic velocity takes place at the volumetric ratio of the streams of 0.5). The important feature of the FD device is also the independence of the discharge flow from the changing parameters of the end user system downstream (such as back pressure), indicating that the FD device creates supersonic flow and there is no downstream communication past the Mach barrier (or upstream either).
Referring to FIG. 1 it may be seen that when there is no liquid—the ratio equals one, if there is no gas—the ratio β equals zero. When there is 50% liquid and 50% gas (two phase flow)—the ratio β is equal 0.5 and the sonic velocity is much lower than in gases and liquids. The equation of sonic speed is as follows:
                              S          2                =                  kP          P                                    (        1        )            
Where: k=isentropic exponent, equal to the ratio of specific heats; P=pressure; p=density of the medium. For determining the isentropic exponent, the following equation was developed:
                                                                        k                g                            ⁡                              (                                  k                  +                  1                                )                                      -                          2              ⁢              k                                                          k              g                        -            1                          =                              k            ⁢                                                  ⁢                          β              ⁡                              [                                  1                  +                                                            (                                                                        1                          β                                                -                        1                                            )                                        2                                                  ]                                              -                      2            ⁢                          (                                                1                  β                                -                1                            )                        ⁢                          (                                                1                  ɛ                                -                1                            )                                                          (        2        )            
Where: kg=isentropic exponent of as in the mixture; ε=critical ratio of pressures.
As the result of exchange of motion impulses between the working and injected streams, the sonic velocity in the mixing chamber is reduced. The stream at the entrance to the mixing chamber (throat) has a velocity equal to or larger than the local sonic velocity. As the result of the stream deceleration the temperature and pressure at the exit of the mixing chamber increase. The pressure becomes higher than the saturation pressure at the saturation temperature of the mixture. At the specific design geometry, the discharge pressure can increase by few times higher than the pressure of the working media. The liquid phase in the mixing chamber has a foam type (plasma) structure with a very highly turbulized surface area, therefore the dimensions of the FD device are very small when compared with conventional surface type heat exchangers. It should be indicated that the FD is a constant flow device.
Substantial differences in the above described process take place at small injection coefficients. The reduction of the flow rate of the injected water/fluids at the constant steam flow rate leads to the increase of the water temperature to the saturation temperature corresponding to the pressure in the mixing chamber and, because of the shortage of water for condensation of all steam, while the FD device's heat exchange operation continues, its pumping performance is proportionally reduced. This mode determines the minimum injection coefficient. At this mode the operational and geometry factors influence the characteristics of the FD device. With the increase of the injection coefficient, when the flow rate of the injected water (as the result of the reduction of back pressure) is increased, the water temperature in the mixing chamber is reduced. At the same time because of velocity increase in the mixing chamber the water pressure is reduced. The increase of the flow rate of injected water leads to the reduction of the pressure at the entrance into mixing chamber up to the saturated pressure corresponding to the temperature of the heated water. Reduction of the backpressure doesn't cause the increase of the water flow rate because further pressure drop in the mixing chamber is impossible. This pressure drop which determines the flow rate of the injected water can't be increased. Further reduction of backpressure at this conditions leads to flashing of the water at the mixing chamber.
The cavitation of water in the mixing chamber determines the maximum (limiting) injection coefficient. It should be noted that this operational condition is the working mode of the FD. The FD operates with high expansion and small compression ratios.
Recent analysis and testing of FD's resulted in a conclusion that conversion of the internal (interparticle) energy of overheated liquid into the work can be achieved both with the presence of a “cold” heat-transfer agent and without it. Furthermore, under specific pressure values at the entrance into the apparatus and specific internal geometric parameters, the “cold” liquid itself becomes the two-phase medium before the pressure jump. From this phenomenon follows a principally important conclusion that under the desired conditions the internal (interparticle kinetic) energy of liquid could be transformed into useful work.
In addition to the foregoing, other subject matter disclosed herein relates to the production of mechanical work and in particular to direct contact heat exchangers producing heat, and hydraulic, pneumatic and steam turbines for driving electrical generators, hydraulic pumps, compressors, heat and two-phase pumps.
Many buildings in the United States and around the world use steam for space heating, cooling and domestic hot water supply. The steam condensate is sometimes returned to the steam generating source or discharged to the city sewer system. In order to reduce the condensate temperature from 220 F to about 110 F (the city sewer requirement) the condensate is mixed with cold potable water. Such systems operate with substantial electric, heat and water losses and sewer discharge rate. All discharge rates are assessed and paid for.
Existing alternative sources for waste water use for electricity production include geothermal, solar thermal and bottoming cycles of large steam (fossil and nuclear), reciprocating internal combustion and diesel power plants, chemical processes, and various industries. Typically, the energy in boiling waste water is transferred to a thermodynamic working fluid (binary cycles) to generate electrical power. Because the water or other waste streams are only under moderately high temperature and pressure, the working fluids operate in the two-phase region with low energy conversion efficiency (15 to 20%) and often suffer from poor durability.
In 2000 the California Energy Commission sponsored a project (CEC-500-2005-079) which briefly (for operational intervals of minutes) demonstrated that a two-phase turbine with a long curved reaction expansion nozzle could operate at turbine efficiency close to 50%. The turbine used water heated to 435° F. and 350 psig. The principal difference of the proposed invention from the above turbine is the use of low temperature readily available renewable waste liquids and gases and application of advanced transonic nozzles capable of creating very high discharge pressure trust.
A two-phase reaction turbine for obtaining mechanical energy is known, which includes a radially outward flow turbine having a rotor with nozzles which extend from an inner inlet passage to the rotor periphery with a substantially constant pressure drop per unit length of nozzle, with a first order surface continuity along the surface of each nozzle and with a nozzle profile which allows two-phase flow without substantial lateral acceleration. The turbine also has an outer casing which is rotated by flow entering the casing openings creating an additional mechanical work.
The known reaction turbine has the disadvantage that it is not possible to obtain the maximum mechanical energy for the turbine from its rotor, since the torque generated in the rotor during flowing out of the working medium from its channels is limited by the discharge pressure of the environment.
A two-phase reaction turbine for obtaining a mechanical energy is known, which includes supplying a working medium into the channel of the rotor of the turbine and acceleration of the working medium during flowing out from the channels in one direction along a circumference perpendicular to the radius of the rotor with providing of rotation of the rotor.
The disadvantage of this known method is insufficiently high quantity of obtained mechanical energy because during the flowing out of the working medium through four channels of the rotor and its supply into a space formed by the casing in the form of the blade turbine around the rotor and flowing out through the openings in the casing between the instant of the turbine, the working medium located between the blades in instant of contact with streams of channels of the rotor is expelled, “knocked out”, being accelerated to the speed of the stream from the channels of the rotor, for which a part of energy of the stream is used. During flowing out through the openings in the casing in the form of a radial blade turbine, there are losses for acceleration of the working medium in radial blades from centrifugal forces. In addition, there are losses for ventilation during circulation of the working medium between the blades due to flowing out through openings in the casing. Also, from the rotating casing in the form of a radial blade turbine, the working medium flows out with a speed which is significantly different from the speed of rotation of the casing, which leads to losses of energy.
A jet reaction turbine is also known, which has a working wheel formed as a tube with a closed end, connected coaxially with the shaft, arranged with a possibility of rotation, with at least one pair of pipe with open ends radially fixed on the tube at opposite sides, a casing arranged with the possibility of rotation and surrounding the wheel, a housing which surrounds the wheel and the casing and has openings for arrangement of the shaft, and nozzles for supplying and discharging of the working medium. At least one pair of pipes with open ends is fixed on the casing at the opposite sides. The casing and the working wheel are arranged on the same shaft.
The disadvantage of this known turbine is its fixed connection of the casing and the working wheel arranged on the single shaft, and to rotation of the working wheel and the casing in one direction, that provides obtaining of mechanical energy only from one casing, while pipes of the working wheel are only throttling the pressure of supply of the working medium by the elements of the turbine, which leads to useless losses of energy and low turbine efficiency.
A radial turbine with two shafts is known, which has a Segner wheel formed as a tube with a closed end connected coaxially with the shaft and arranged with the possibility of rotation, at least one pair of pipes fixed on the tube radially at opposite sides and having open ends which are bent in opposite sides from their axes, wherein the axes of the bent open ends of the pipes are perpendicular to a plane extending through the axes of the pair of pipes and the axis of the tube, wherein in a wall of the pipe openings corresponding to the pipes are provided, a casing is connected coaxially with the shaft and arranged with the possibility of rotation and surrounding the Segner wheel, a housing surrounding the Segner wheel and the casing with openings for arranging the tube of the Segner wheel and shafts of the Segner wheel and the casing, and a nozzle for flowing out of a working medium. The casing is formed as a blade turbine.
The disadvantage of this known turbine is that in the casing formed as a blade turbine the blades are fixed to the disc along its end, which increases a centrifugal load on the blades due to an additional moment and an assembly of fixing of the blades is incapable of bearing a high load, that requires a reduction of circumferential speeds of the blade turbine and decreases the efficiency of the blade turbine. For passage between the blades, a stream of the working medium from the nozzles of the rotor must be directed to the blades at a certain angle which is determined by the shape of the blades and the shape of the stream from the nozzles. In the known turbine the stream of the working medium from the nozzles is supplied onto the blades under different angles, which on an average leads to increased angles acceptable to the turbines with a separate nozzle apparatus and to decrease of the efficiency.
The use of a hollow rotor (Segner wheel) leads to losses for friction due to generation in a hollow of the rotor a circulation of the working medium which is entrained due to viscosity on the walls and an opposite flow in a medium part of the hollow of the rotor (Segner wheel), or in other words the formation of a pair whirl. As a result the power taken from the rotor with the hollow is lost. With a partial supply of a working medium to the casing (blade turbine) from four nozzles of the rotor (Segner wheel), which rotates in an opposite direction, the working medium located between the blades at a low pressure in a moment of contact with the streams from the nozzles of the rotor, is expelled, “knocked out”, being accelerated to a speed of the stream supplied from the nozzles of the rotor, for which a part of the energy of the stream is used.
In the casing (blade turbine) there are losses for acceleration of the working medium in radial blades from centrifugal forces. In addition, there are losses for ventilation due to circulation or the working medium between the blades during flowing out through the openings in the casing. Also, from the rotating casing in form of a blade turbine, the working medium flows out with a speed which significantly differs from the speed of rotation of the casing, which leads to energy losses.
The known turbine also has a complicated construction and a complicated technology for its manufacture due to the use of a blade turbine as a casing.
A method of obtaining mechanical energy from a turbine is known, which includes supplying a working medium into channels of a rotor of a turbine, accelerating the working medium while flowing out from the channels in one direction along a circumference and normally to a radius of a rotor so as to make the rotor rotate, supplying the working fluid from the rotor channels into a space created within a casing above the rotor where it interacts by friction with the casing while flowing out through openings of the casing so as to accelerate in one direction and to make the casing rotate, forming the space in the casing closed and extending along a radius of the circumference along outlet openings of the rotor channels, and accelerating the working fluid flowing out through the openings of the casing along a circumference and normally to a radius of the casing in a direction opposite to a direction of flowing out from the rotor.
The disadvantage of this known method is insufficient high quantity of obtained mechanical energy because the nozzles are not of transonic type and do not provide additional thrust.
While existing systems described above are suitable for their intended purposes, improvements remain in the harvesting of thermal energy of the liquid while improving the efficiency of heat harvesting and providing reliable and stable operation of the system in a wide range of operating parameters, and while existing hot water and condensate collection systems are suitable for their intended purposes, the need for improvement remains, particularly in providing a system that improves the overall cycle thermal efficiency.